The first donation page I encountered was set up as though I have a business (a company). I do not. The other problem I had on the page was I couldn't change the donation $$$ amount. I wanted to donate more than what was on the page.

So I tried it another way of making a donation and this time the page I landed on assumed that I'm a reseller. I'm not.

I assume you're referring to the Share-it page.
The value for “Quantity” can be increased. (“Unit Price” is currently at €5.00.)
If you have a PayPal account, you could also send the money directly to contact(ät)xnview(d0t)com.